/* Copyright (c) 2020 XEPIC Corporation Limited */
/*
 * Copyright (c) 2003-2014 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include <assert.h>
#include <veriuser.h>
#include <vpi_user.h>

#include "priv.h"

static PLI_INT32 delay_callback(struct t_cb_data* cb) {
  (void)cb; /* Parameter is not used. */
  vpi_printf("XXXX delay_callback called.\n");
  return 0;
}

int tf_isetdelay(PLI_INT32 delay, void* ss) {
  vpiHandle sys = (vpiHandle)ss;
  int unit = vpi_get(vpiTimeUnit, sys);
  int prec = vpi_get(vpiTimePrecision, 0);

  struct t_cb_data cb;
  struct t_vpi_time ct;

  if (pli_trace) {
    fprintf(pli_trace,
            "%s: tf_isetdelay(%d, ...)"
            " <unit=%d, prec=%d>;\n",
            vpi_get_str(vpiName, sys), (int)delay, unit, prec);
  }

  /* Convert the delay from the UNITS of the specified
     task/function to the precision of the simulation. */
  assert(unit >= prec);

  while (unit > prec) {
    PLI_INT32 tmp = delay * 10;
    assert(tmp > delay);
    delay = tmp;
    unit -= 1;
  }

  /* Create a VPI callback to schedule the delay. */
  ct.type = vpiSimTime;
  ct.high = 0;
  ct.low = delay;

  cb.reason = cbAfterDelay;
  cb.cb_rtn = delay_callback;
  cb.obj = 0;
  cb.time = &ct;
  cb.value = 0;
  cb.user_data = 0;
  vpi_register_cb(&cb);

  return 0;
}

int tf_setdelay(PLI_INT32 delay) {
  return tf_isetdelay(delay, tf_getinstance());
}
